The Effects of Filtration on Pressure Drop and Energy Consumption in Residential HVAC Systems

The use of high-efficiency HVAC filters is a common strategy to control exposure to airborne particulate matter in residential buildings. However, high-efficiency filters generally have a higher pressure drop and are widely assumed to have large energy penalties. In this paper, we explore the underlying theoretical energy implications of high-pressure-drop filters and we present the results of a four-month-long period of detailed energy monitoring of two air-conditioning systems in a test home in Austin, Texas. A theoretical analysis shows that the magnitude of potential energy impacts associated with high-efficiency filters are overall likely to be small and can result in either a net savings or additional expenditure, depending on the system. The measured results in the test systems confirm these findings, and energy consumption generally did not differ with high-efficiency filters compared to low-efficiency filters. These results suggest caution when assuming that high-efficiency filters require more energy than low-pressure-drop filters in residential HVAC systems.